I disagree that the topic has been beaten to death. I am always looking for a better picture to illustrate the visual impact of the wider tire. Perhaps a rear shot would do that? I dunno.
Both the stock 19" and 20" wheels are 10.5" wide in the rear. Most (all?) of the people that have installed 305s have been running the 20" wheels. Can anyone see why they wouldn't also work on the 19" wheels (since they are the same width)? My Contis are about done for and I'm looking to upgrade to 305 P4S... but I have the stock 19" front/rear wheels rather than the 19"/20" wheels.
It's probably all in my head, but the traction on acceleration and hard banking seems significantly better. Don't really see how 20 mm of rubber can make that much of a difference, but the car just feels much more predictable.
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.